Malicious PDF — malware analysis report

Static analysis result for SHA-256 a785ec811bec4e16…

MALICIOUS

PDF

81.7 KB Created: 2021-09-08 07:35:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0c3dc8feeb5b343e72ecc3d498260f0c SHA-1: 262aee22bcef9db99ac782c13e139e9bc2e8d735 SHA-256: a785ec811bec4e1649212b0cdd088574da740e2a5eac659e25a42b7e64eb6dbe
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to domains that appear to be compromised or used for hosting malicious content. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using disposable hosting for a link farm, suggesting an attempt to obscure the true destination or evade detection. The presence of multiple links to compromised CMS upload storage further supports a malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://diplomat2014.ru/ckfinder/userfiles/files/79901846245.pdf In PDF document text
    • http://dchs1961.com/clients/871949/File/lixopo.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/8h7ivl17kcln5uhcdnt8nle2ev/xekofidiruvinonumedafon.pdfIn PDF document text
    • https://pieseautocomenzi.ro/userfiles/file/93746229797.pdfIn PDF document text
    • https://dolphinsolutions.net/ckfinder/userfiles/files/wuxavavi.pdfIn PDF document text
    • https://vakukh.ru/wp-content/plugins/super-forms/uploads/php/files/744a6891f656a19cd8ee6dd870aca431/55581055719.pdfIn PDF document text
    • http://caphegiabao.com/upload/fck/file/wixasofoxifep.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/girarevonanabizusaf.pdfIn PDF document text
    • https://bojovicsirogojno.com//files/vemet.pdfIn PDF document text
    • http://www.chinahkcarplate.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac30d01a2b7---99848463471.pdfIn PDF document text
    • http://ampletrekking.com/userfiles/file/51127860313.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084fd4c35b38---8997209902.pdfIn PDF document text
    • http://studiophotosfashion.it/userfiles/files/62464575931.pdfIn PDF document text
    • http://countrysquirefoods.com/wp-content/plugins/formcraft/file-upload/server/content/files/160913028eef3f---64723092675.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/9593765468.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160743356eb829---zemekufokuzaz.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f5fcae08d3---19673231069.pdfIn PDF document text
    • http://tavernadelsnoguers.com/wp-content/plugins/super-forms/uploads/php/files/4cedefa5fff66f998628d82b8fb91f6c/jinenal.pdfIn PDF document text
    • https://nucamsa.es/userfiles/files/6419635445.pdfIn PDF document text
    • http://dawahcity.com/userfiles/file/75301331306.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c998f864d8---nebew.pdfIn PDF document text
    • http://olsztyntransportmedyczny.pl/userfiles/file/dedixal.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/82176024204.pdfIn PDF document text
    • http://kryotherapie.net/neu/userfiles/file/41213885689.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=ejercicios+vocales+para+imprimir+pdfPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d699.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD699 20060 bytes
SHA-256: db7d590b8b9a1540f6eb98c7e1c0b924a0ed0cc36a194f870a4eb693727b57ea
font_01_sfnt_off00010834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10834 10756 bytes
SHA-256: 5f855e3ed6157bd7599f4a8905ffb19018d2536f8ba175ac0fbb41f3659ce35c
font_02_sfnt_off000120e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120E4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1